JPS6255717B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a hybrid integrated circuit in which various chip-shaped components are mounted on a substrate.

In order to streamline the manufacturing of circuits, a method has been proposed in which the shapes of the components are almost uniform regardless of their types, and these components are mounted on a circuit board. In such a method, the circuit component has no leads and is generally chip-shaped and includes, for example, a pair of cap-shaped electrodes. These chip-shaped parts are manufactured by the applicant of the present application, for example, in Japanese Patent Application No. 54-58888 (Japanese Unexamined Patent Publication No. 55-55).
151394).
That is, the chip-shaped component is placed at a predetermined position on the template, and a circuit board, on which adhesive resin has been applied in advance at a predetermined position, is placed on top of the template, and these circuit boards and the template are placed on top of each other. Turn the chip-shaped component upside down and transfer it to the circuit board side, cure the adhesive resin and temporarily fix the chip-shaped component to the circuit board, and then use solder to connect the electrodes of the chip-shaped component to the conductive circuit board. It is mounted in such a way that it is electrically connected to the sexual pattern.

The circuit board used in such a method is, for example, one based on phenolic resin, on which a copper foil is formed on at least one surface, and a conductive wiring pattern is formed by etching. It is. Circuit boards made of such phenolic resins are relatively inexpensive, and therefore the resulting circuits are also inexpensive. Also, since the heat dissipation coefficient is small, it can be repaired using a soldering iron. It also has the characteristics of good processability and therefore high productivity of substrates.

However, if a circuit that generates heat is formed on such a phenol substrate, a separate heat sink must be provided because the heat dissipation coefficient is low. Furthermore, the material of this substrate has a predetermined dielectric constant, which has a non-negligible effect on ultra-high frequency circuits such as VHF, UHF, SHF, and ENF. That is, the signals processed in the circuit formed on the phenol substrate have a frequency limit.
Furthermore, when a high-performance circuit such as a high S/N ratio circuit or a high impedance circuit is formed on a phenol substrate, problems arise with the insulation properties of the substrate and surface leakage. Therefore, it is necessary to use a special material such as glass epoxy for the substrate, and to apply a high-performance ink for the solder mask. Furthermore, in order to prevent uneven distribution of the arrangement density of components on the circuit board, it is necessary to form at least a part of the circuit board into a double-sided pattern and to mount components on both sides of the circuit board.

In order to improve the heat dissipation of the circuit board, it is conceivable to use aluminum or alumina ceramic for the board. However, making substrates using these materials not only increases costs, but also causes the problem that they cannot be repaired with a soldering iron due to their large heat dissipation coefficients. For use in ultra-high frequency circuits, it is conceivable that the substrate be made of materials such as alumina ceramic or glass epoxy.
Processability is poor, and cost increases significantly. Furthermore, when glass epoxy or other special materials are used instead of phenolic resin to form high-performance circuits, the cost of materials increases and the number of processing steps increases, which increases processing costs. . Furthermore, in order to prevent high-density mounting of components on a part of the circuit board, the entire surface of the board must be patterned on both sides, which increases processing and material costs and reduces reliability. be.

As described above, the needs required of circuit boards are complex and diverse, and there is no single board that satisfies all of them.

Therefore, it is considered to construct a circuit board by combining a main board and a sub-board of different materials or structures, but in this case, it is necessary to combine both and securely fix them. become. If they are not securely fixed, there will be a difference in coefficient of thermal expansion due to the different materials, resulting in defects such as the fitted sub-board falling off from the main board. Moreover, if a special process is added to fix this composite main board and sub-board, this will increase costs and offset the effect of material cost savings. .

The present invention has been made in view of these problems, and involves preparing a main substrate and a sub-substrate each having a predetermined conductive pattern formed thereon and having different materials or structures. A circuit in which an opening having the same shape as the sub-board is formed in the board, the sub-board is fitted into the main board through the opening, and an adhesive resin is applied for temporarily fixing the chip-shaped parts. At the same time as applying the adhesive resin to the substrate, the adhesive resin is also applied to the joint between the main board and the sub-board, thereby joining the joint between the main board and the sub-board, and applying the adhesive resin to the joint between the main board and the sub-board. The present invention relates to a method of manufacturing a hybrid integrated circuit, characterized in that electrodes of chip-like components temporarily fixed with resin are electrically connected to conductive patterns of a composite circuit board. Therefore, in order to fix the bonded portion between the main board and the sub-board, it is possible to reliably fix the two by using the adhesive resin for temporarily fixing the chip-shaped parts, without providing a new process.

The present invention will be described below by way of example with reference to the drawings. This embodiment shows an embodiment in which the present invention is applied to a hybrid integrated circuit for audio, and FIG. 1 is a block diagram showing the manufacturing process of this hybrid integrated circuit, and FIGS. Figure 3 is a flowchart of this manufacturing process. Note that FIG. 2 particularly shows the process of creating a composite board, and FIG. 3 shows the process of mounting a chip-shaped component on this composite board.

Below, the steps shown in these figures will be explained step by step. In FIG. 1, the main substrate material 1 for obtaining the main substrate may be a phenolic resin, which is inexpensive and has good workability. As shown in Figure 2, this material 1
Copper foil 2 is adhered to the surface of and chemically etched. Then, a conductive wiring pattern 3 is formed. Furthermore, this is subjected to external processing and punching.
This is done, for example, by a pressing method, by finishing the outer shape of the material 1 into a predetermined shape, forming a through hole in this material 1, or inserting a sub-board into the composite as shown in FIG. Rectangular openings 4, 5, 6, and 7 are formed for this purpose. Note that these processes are performed simultaneously. In this way, the main substrate 8 is obtained.

Next, the sub-boards 9, 1 are fitted into the openings 4, 5, 6, 7 of the main board 8 to be combined.
0, 11, and 12 will be described. First, the sub-board 9 is for forming an ultra-high performance circuit such as an audio preamplifier or head amplifier on it, and its substrate material 13 is made of glass epoxy resin. Then, a copper foil 14 is bonded to the surface of this material 13, a wiring pattern 15 is formed by chemical etching, and external processing and punching processing are performed so that the shape corresponds to the above-mentioned opening 4, and a sub-board 9 is formed. is obtained.

Next, the sub-substrate 10 is for forming an ultra-high frequency circuit such as a tuner thereon, and its substrate material 16 is made of, for example, alumina ceramic. Note that this substrate material 16 has already been machined into a shape that corresponds to the opening 10 described above. First, a silver electrode 1 is placed on the surface of this material 16.
7 is printed and solidified by firing at a temperature of about 800°C to 900°C. Then, if necessary, a resistor 18 is printed and likewise hardened by firing. In this way, the sub-substrate 10 is obtained.

Next, the sub-board 11 is used to form a circuit having heat-generating components such as a power amplifier thereon, and the board material 19 is an aluminum plate having excellent heat dissipation properties. Since the aluminum substrate material 19 is electrically conductive, an insulating layer 20 made of an insulating polymer film is first applied to the adhesive material 21.
A copper foil 23 is further bonded to the surface of the insulating layer 20 via an adhesive layer 22 (see FIG. 4). This copper foil 23 is then chemically etched to form a conductive wiring pattern 24. The sub-board 11 is obtained by processing the outer shape and punching holes. Note that FIG. 4 shows a cross section of the aluminum substrate 11 before etching.

Finally, regarding the sub-board 12, this board 12 is used to prevent extremely high mounting density of components on a part of the circuit board. 25
may be, for example, the same material as the main substrate 8, phenolic resin. Copper foils 26 and 27 are bonded to the upper and lower surfaces of this material 25, respectively, and these copper foils 26 and 27 are chemically etched at the same time. As a result, wiring patterns 28 and 29 are formed on both sides of the substrate material 25. After processing the outer shape and punching holes, double-sided patterns 28, 2
A sub-substrate 12 having 9 is obtained. Note that the four sub-boards 9, 10, 11, and 12 mentioned above are all the main board 8.
It has almost the same thickness.

As described above, the main board 8 and the sub boards 9, 1
However, in this embodiment, four sub-substrates 9, 10, 1 made of mutually different materials are obtained.
1 and 12 are used, and these are combined with the main board 8. However, if necessary, two boards may be used for at least one of these sub-boards 9, 10, 11, and 12. The above may be used, or these sub-boards 9, 10, 11, 1
One or more of the sub-boards may be omitted. Alternatively, a sub-board made of a different material or structure may be combined with the main board 8. That is, the type and number of such sub-boards can be arbitrarily selected depending on the properties of the hybrid integrated circuit finally obtained.

Next, the sub-board 9, 1 obtained as above
0, 11, 12 are inserted into the main board 8 and combined,
Describing the process of obtaining the composite substrate 30, the fifth
As shown in the figure, the above sub-boards 9, 10, 11, 12
As mentioned above, the rectangular openings 4, 5,
6 and 7, each having substantially the same shape. Further, these sub-boards 9, 10, 11, and 12 are each configured to have approximately the same thickness as the main board 8, for example, 1.6 mm. Therefore, the sub-boards 9, 10,
11, 12 into the openings 4, 5, 6, 7, these sub-boards 9, 10, 11,
12 is composited so that it is included in the plane of the main substrate 8, and a flat composite substrate 30 having a uniform thickness of, for example, 1.6 mm is obtained. Note that the sub-boards 9, 10, 11,
It is important that the composite substrate 30 into which the composite substrate 12 is fitted is formed to be flat and have a uniform thickness. That is, in the subsequent steps, the composite substrate 30 is coated with a protective coating resin for solder resist, a resin for insulation, and
Then, an adhesive resin for temporarily fixing the chip-shaped parts is applied by printing, but in these steps, since the composite substrate 30 is flat and has no unevenness, printing can be performed with high precision. Moreover, uniform application is achieved. Also, this composite board 3
0 on the template, it is also possible to transfer the chip-shaped parts to this composite substrate 30 at once using the adhesive resin.

This combined process is carried out, for example, by the apparatus shown in FIG. As shown in the figure, this device
It includes an upper mold 31, a lower mold 32, and a male mold 33. A recess 34 for receiving a male mold 33 is formed in the lower mold 32. So first, male type 3
3 to the lower mold 32, at least the sub-boards 9 and 1
0, 11, and 12, and thereby the sub-substrates 9, 10, 1 are placed in the recess 34 of the lower mold 32 and above the male mold 33.
A recessed portion 35 is formed for receiving each of 1 and 12. The sub-boards 9, 1 are placed inside these recesses 35.
Store 0, 11, and 12 respectively. Next, lower mold 3
The main substrate 8 is placed on the upper surface of the lower mold 32, and the main substrate 8 is positioned with respect to the lower mold 32 by positioning pins 36 implanted in the lower mold 32. Next, the upper mold 31 is crimped onto the lower mold 32 while being guided by the pins 36. Next, the male mold 33 is moved upward to press the sub-boards 9, 10, 11, and 12 onto the lower surface of the upper mold 31. As a result, the sub-boards 9, 10, 1
1 and 12 are openings 4, 5, 6 of the main board 8, respectively.
It will be included in 7. Moreover, the sub-board 9,
External dimensions of 10, 11, 12 and openings 4, 5,
6 and 7 are becoming smaller, the sub-boards 9, 10, 11, and 12 are temporarily fixed to the main board 8 by friction of the fitting portions.

The thus obtained composite substrate 30 is then printed with a protective coating resin as shown in FIG. The resin used here may be, for example, an epoxy resin or an acrylate resin. This resin printing is performed by a method such as silk screen printing. Then, heat is applied to harden or bake the resin. As a result, a protective coat resin layer 37 is formed on the surface of the composite substrate 30. The purpose of this resin coating is primarily to apply a solder resist, and solder will not stick to the resin-coated portion during solder dipping, which will be described later. The second purpose of this resin coat is as an insulating coat. That is, the surface of the ultimately exposed portion of the wiring pattern of the composite substrate 30 is covered with the resin layer 37 and is insulated in advance.

By the way, in this embodiment, the main substrate 8 and the sub-boards 9, 10, 11, and 12 are not printed with the resin 37 in advance as described above, but after the outer shape and hole punching are performed, the two are combined. A resin 37 is applied. Therefore, the step of coating the main substrate 8 and the sub-boards 9, 10, 11, 12 with resin can be completed only once.

Next, on this composite substrate 30, insulating resin printing is performed as shown in FIG. This resin printing is performed using, for example, epoxy resin. This resin is also printed by a method such as silk screen, and then cured or fired by applying heat, thereby forming an insulating resin layer 38 on the composite substrate 30. The first purpose of forming this insulating resin layer 38 is to insulate the cross pattern portions of the wiring pattern on the composite substrate 30 that intersect with chip-shaped components. The second purpose is to print a symbol mark on the resin, which is colored with a pigment mixed therein.

Chip-shaped parts are mounted on the composite substrate 3 after the process shown in FIG. 2 in the process shown in FIG. 3. This process will be explained in order below. First, as shown in FIG. 9, adhesive resin 40 is applied to the surface of the composite board 30, that is, at the chip-shaped component mounting position on the pattern surface, by a screen printing method. Ru. This adhesive resin 40
is for temporarily fixing a chip-shaped component onto the composite board 30.

The printing operation of this adhesive resin will be explained sequentially with reference to FIGS. 10A to 10H.
As shown in Figure A, the frame 41 is rotated clockwise about the pin 42 to hold the screen 43 stretched on the frame 41 in a state separated from the composite substrate 30 on the mounting plate 44. I'll keep it.
In this state, the scraper 45 is lowered and brought into contact with the screen 43. Then, the scraper 45 is moved to the left in FIG. 10B along the frame 41 by a driving means (not shown). Then, the scraper 45 moves in the length direction of the screen 43 while rubbing the adhesive 40 in a semi-fluid state on the surface of the screen 43, and fills the transparent portion of the screen 43 with the adhesive. When the scraper 45 moves to a predetermined position, it rises and separates from the screen 43.

Next, a hydraulic cylinder for driving the frame is operated, and the frame 41 is moved by a crank arm (not shown).
rotates counterclockwise about the pin 42 as shown in FIG. 10C. At this time, screen 4
As shown by the chain line in FIG. 10C, it must be noted that 3 stands still parallel to the composite substrate 30 and at a predetermined distance from the composite substrate 30. That is, when the frame 41 is rotated and moved to the operating position and becomes horizontal, the screen 43 does not come into contact with the composite substrate 30.

In this state, the squeegee 46 descends. The squeegee 46 displaces the screen 43 downward against its tension, thereby causing the screen 43 to move to the tenth position.
It comes into contact with the composite substrate 30 as shown by the solid line in Figure C. In this state, a driving means (not shown) is activated, and the squeegee 46 moves to the right as shown in FIG. Move to the 30 side. This will cause screen 4
An adhesive 40 is applied to a predetermined position of the composite substrate 30 corresponding to the transparent portion 3. When the squeegee 46 moves to a predetermined position, the squeegee 46 stops its horizontal movement and moves upward and away from the screen 43.

In order to more clearly understand the superiority of this device by comparing it with the operation of the device of this embodiment, we will now describe the operation of a screen printing device that has been widely used in the past. like,
Immediately thereafter, the frame 41 was rotated clockwise about the pin 42. Therefore, the adhesive 40 adhering to the transparent portion of the screen 43 was drawn to form adhesive threads 47. Since the screen 43 rotates around the pin 42 when separated from the substrate 30, the adhesive thread 47 becomes more inclined as it approaches the center of rotation of the frame 41. This adhesive thread 47 fell down and was attached to a position other than the desired position on the substrate 30. As a result, if the conductive pattern on the substrate 30 is covered with adhesive, there is a problem that when circuit components are soldered-dipped, the circuit components cannot be electrically connected correctly.

Therefore, in this embodiment, after the squeezing operation is completed, as shown in FIG. 10F, the squeegee 46 is released from the screen 43, and the frame 41 is held horizontally without rotating, and kept stationary for a certain period of time. There is. When both the squeegee 46 and the scraper 45 are apart from the screen 43, the screen 43 is held parallel to the composite substrate 30 with a predetermined gap therebetween, as described above. For this purpose, use the squeegee 46
When the screen 43 separates from the composite substrate 30 as the screen 43 rises, the threads 47 of the adhesive 40 will extend upward in a substantially vertical direction. This adhesive 4
By holding the screen 43 approximately parallel to the composite substrate 30 for 2 to 6 seconds, the threads 47 of 0 are separated from the screen 43 and crushed by the fluidity of the adhesive 40, as shown in FIG. 10G. It becomes almost flat and disappears. That is, while the adhesive 40 is applied to a predetermined position on the composite substrate 30, the adhesive 40 does not protrude from the predetermined position and does not cover the conductive pattern of the composite substrate 30, which may cause poor connection of components. Nor.
Note that this device is effective in preventing stringiness, especially when the resin to be applied is thick.

After this, as shown in FIG. 10H, the frame 41 is rotated clockwise about the pin 42 by the operation of the hydraulic cylinder, and the composite substrate 3
0 is removed from this applicator. When the frame 41 further rotates clockwise to a predetermined position, the scraper 45 descends and adheres to the screen 43, preparing for the next cycle of operation. Needless to say, the same operation as above is repeated in the next cycle.

The screen 43, whose peripheral edge is held by the frame 41 and stretched under a predetermined tension, is made of mesh made of Tetron (registered trademark), and both surfaces of this mesh are coated with resin. The thickness of the resin-coated screen 43 is the same as that of the adhesive resin 40 applied to the composite substrate 30.
In this example, it is quite thick, for example, 400 μm to 500 μm.
It is becoming. This screen 43 has a portion that is not coated with resin, and this portion forms a transparent portion. Then, the adhesive resin 40 previously held in this transparent portion is applied to the composite substrate 30 using the above-mentioned squeegee.

By the way, the adhesive resin 40 is applied to the main substrate 8 and the sub-substrates 9, 1 which are combined with each other as shown in FIG.
It is also applied to the joints where 0, 11, and 12 fit together at the same time.

Further, since the adhesive resin 40 is then cured and solidified in a photocuring furnace and a thermosetting furnace, which will be described later,
The joint strength between the main substrate 8 and the sub-substrates 9, 10, 11, 12 is improved.

Moreover, in applying the adhesive resin 40 to this joint, it is only necessary to form a transparent part at a position corresponding to the joint of the screen 43, and as a result, it is possible to apply the adhesive resin 40 to the joint without adding a new process. Can also be coated with resin. Furthermore, this resin 40
Since the coating is done to form an adhesive layer with a thickness of approximately 400 μm to 500 μm,
The holding force for holding the sub-boards 9, 10, 11, and 12 on the main board 8 is large, and the joints are sufficiently reinforced. FIG. 11 shows the composite substrate 30
2 shows a resin layer 40 formed at the joint.

Next, the process of mounting chip-shaped circuit components on the composite substrate 30 on which the adhesive resin layer 40 has been formed by coating will be explained mainly with reference to FIG. Various chip-shaped parts 51 such as capacitors, resistors, jumper cross conductors, diodes, etc. are housed in a separate state in a container 52 of the hopper. These parts 51 are intermittently supplied by the action of the shutter device 53 and guided to the placement magazine 55 through the parts transfer pipe 54. This placement magazine 55 is for guiding various parts 51 to respective predetermined positions. And this magazine 5
Chip-shaped part 51 guided to a predetermined position by 5
is further guided to a placement plate 56, and a cylindrical chip-shaped component 51 that has been sent in a vertical position is overturned by a rollover mechanism provided on this placement plate 56. When the shutter arranged at the lower part of the arrangement plate 56 is opened, the chip-shaped parts 51 fall and are stored in the component storage recesses 58 of the template 57 arranged at the lower part of the arrangement plate 56.

On the other hand, the composite substrate 30 coated with the adhesive resin 40 as described above in the steps shown in FIGS. is superimposed on the template 57 housed in the recess 58 and is lightly pressed. Next, the template 57 and the composite substrate 30 are turned upside down while still being superimposed, so that they are turned upside down. As a result, the template 57 is positioned on the upper surface of the composite substrate 30. Then template 5
7 and the composite substrate 30 are pressed together by a pressure means, and the cap-shaped electrodes at both ends of the chip-shaped component 51 held in the recess 58 of the template 57 are pressed to the conductive pattern of the composite substrate 30. At the same time, this chip-shaped part 51 is brought into reliable contact with the adhesive resin 40 at a portion of the body approximately at the center in the length direction.

After this, the template 57 placed on the composite substrate 30 is gently removed, and the chip-shaped component 51 is completely transferred onto the composite substrate 30. However, at this stage, the adhesive resin 40 has not yet hardened. Therefore, this composite substrate 30 is first guided to a photocuring furnace 62 by a belt conveyor 61.
Then, the surface portion of the adhesive resin 40 is first cured by the ultraviolet rays. Further, the composite substrate 30 is moved by a conveyor 61 and guided to a thermosetting furnace 63, where the adhesive resin 40 is completely cured to the inside. In this way, the adhesive resin 40 is cured in the photocuring furnace 62.
Since the adhesive resin 40 is cured in the thermosetting furnace 63, the time required for curing the adhesive resin 40 is shortened. Furthermore, if the resin 40 is suddenly placed in the thermosetting furnace 63 and heated, the viscosity of the resin 40 decreases and the resin 4
The flowing resin 40 may cause poor adhesion of the component 51, or the flowing resin 40 may cover the conductive pattern of the composite substrate 30, causing a poor contact.
However, since the outer surface of the resin is previously cured with ultraviolet light in the photocuring furnace 62, flow of the resin 40 is effectively prevented.

With the resin 40 cured in this way,
The chip-shaped component 51 is completely temporarily fixed to the composite board 30. Moreover, this resin 40 is also applied to the joints between the main substrate 8 and the sub-boards 9, 10, 11, and 12 as described above. Therefore, by curing the resin 40, the main substrate 8 and the sub-boards 9, 1
The joint strength between 0, 11, and 12 reaches the necessary and sufficient values.

Next, on the back surface of this composite substrate 30, that is, on the surface opposite to the pattern surface on which the chip-shaped component 51 is mounted and the conductive pattern is formed, a component 65 with a general lead is mounted, if necessary. Ru. Since the general component 65 and the chip-like component 51 are mounted on both sides of the composite board 30 in this way, this circuit has a high component mounting density and can be miniaturized. Next, the patterned surface of this composite board 30 is directed downward to the solder dip tank 64, and the above-mentioned components 5
1 and 65 are electrically connected to the conductive pattern of the composite substrate 30. That is, the cap-shaped lead portions at both ends of the chip-shaped component 51 are connected to the conductive pattern of the composite board 30 by solder, and the general component 65 with leads has the lead portion connected to the conductive pattern by solder. will be connected by. This results in a hybrid integrated circuit. Note that it is not necessary to mount the normal component 65 with a lead, and the chip-shaped component 5
It is possible to obtain a hybrid integrated circuit even with only 1.

Furthermore, in this process, the chip-shaped part 51
As shown in FIGS. 12 and 13, a part of the substrate is mounted at the joint between the main substrate 8 and the sub-boards 9, 10, 11, and 12 to bridge the joint. Chip-shaped part 5 mounted on the joint
One of the pair of cap-shaped electrodes at both ends of the cap-shaped electrode 1 is soldered to the wiring pattern 3 on the main board 8 side, and the other electrode is soldered to the wiring pattern 15 on the sub-board 9, for example, by using the solder dip. and are electrically connected.
Therefore, the main board 8 and the sub-boards 9, 10, 11, 12 are more firmly connected via this chip-shaped component 51. Also, the adhesive resin 40 of the chip-shaped component 51 to be mounted on this joint part is applied to the first
As shown in Figure 3, the main board 8 and sub boards 9, 10, 1
1 and 12, when this resin 40 temporarily fastens the component 51 and is cured as described above, the adhesive resin 40 and the component 51 at the joint portion will also be applied. Main board 8 and sub board 9, 1
The joints 0, 11, and 12 are firmly connected. Therefore, without adding any new process,
When mounting the chip-like parts 51, simply by changing the mounting position of these chip-like parts 51, the sub-boards 9, 10, 11, 12 can be more reliably attached to the main board 8 by using the chip-like parts 51. It is possible to fix the Furthermore, with this configuration, since the wiring pattern 3 of the main board 8 and the wiring pattern 15 of the sub-board 9 are electrically connected via the component 51, the wiring of both is connected at least in this part. There is no need to electrically connect the patterns 3 and 15.

Furthermore, the feature of the process of this embodiment is that during the solder dip shown in FIG. , 28, 29 are electrically connected. That is, as shown in FIG. 14, the ends of the conductive pattern 3 of the main substrate 8 on the side of the joints with the sub-substrates 9, 10, 11, 12 are exposed without forming the solder resist 37 in advance. I'll keep it. Similarly, the conductive patterns 15, 1 of the sub-boards 9, 10, 11, 12
The tips of the solder resists 7, 24, 28, and 29 on the side of the joint with the main substrate 8 are also exposed without being formed in advance with the solder resist 37. By performing solder dipping in the solder dipping bath 64 in this state, the conductive pattern 3 on the main substrate 8 side and the sub-substrate 9,
10, 11, 12 side conductive patterns 15, 1
7, 24, 28, and 29 are electrically connected by solder 66. In this way, during the solder dip, the wiring pattern 3 of the main board 8 and the wiring patterns 15, 1 of the sub-boards 9, 10, 11, 12 are
7, 24, 28, and 29, there is no need to create a new process or prepare members for connection. It becomes possible to provide a hybrid integrated circuit formed at low cost.

Note that both patterns 3 of the joint part by this solder 66
Since the electrical connections of 15, 17, 24, 28, and 29 are mutually complementary to the electrical connections made through the above-mentioned component 51, one of the means can be used as needed. It is selected for recognition.

Sub-boards 9, 10 constituting the composite board 30,
As described above, 11 and 12 are respectively made of glass epoxy resin, alumina ceramic, aluminum, and phenol resin plates having double-sided patterns.
A circuit corresponding to the material or structure of the material or structure is formed on them. Among these sub-boards 9, 10, 11, and 12, the aluminum sub-board 11 itself also serves as a heat sink, and is designed to absorb heat generated by the power transistor 67, resistor 68, etc. shown in FIGS. 15 and 16. Components are mounted thereon and, for example, a power amplifier is formed thereon. The heat generated by the power transistor 67 and resistor 68 is immediately transferred to the aluminum sub-substrate 11 and then dissipated into the air. Therefore, this sub-substrate 11 is heated to a relatively high temperature, for example, 80°C to 120°C. Therefore, among the circuit components that make up this amplifier, components that are sensitive to heat, such as chemical capacitors 6.
9 is not mounted on this aluminum substrate 11 but is mounted on the main substrate 8 made of phenolic resin. Note that this chemical capacitor 69 is connected to the wiring pattern 3 of the main board 8 and the wiring pattern 2 of the sub-board 11 as described above.
4 to the circuit on the sub-board 11. If a heat-sensitive component such as the chemical capacitor 69 is mounted on the phenol substrate 8 side in this way, the phenol substrate 8 is protected from heat without being heated because of poor heat transfer.

Note that since the aluminum substrate 11 itself has conductivity, even if a through hole is formed, the inner circumferential surface of the aluminum substrate 11 must be insulated. Furthermore, since the processing to form through holes is relatively difficult, in this embodiment, no through holes are formed in this sub-board 11, and components 65 with leads are formed as shown in FIG. Mounted on the main board 8 side, wiring patterns 3, 24
It is connected to the components on the sub-board 11 via. Further, the lead of the power transistor 67 is also bent into an L-shape, passes through a through hole in the main board 8, and is connected to the pattern 3 on the main board 8. Note that this transistor 67 is mounted so that its heat dissipation surface is in contact with the back surface of the sub-substrate 11, so that heat is dissipated effectively.

FIG. 17 shows a further modification of the circuit shown in FIG. 15, in which three aluminum sub-boards 11 are fitted into the main board 8 to form a composite circuit. An R channel low frequency amplification circuit 71 is formed on the first aluminum substrate 11, an L channel low frequency amplification circuit 72 is formed on the second aluminum substrate 11, and a third aluminum substrate 11. A power amplifier circuit 73 is formed therein. With this configuration, each of the circuits 71, 72, and 73 is integrated into a unit, which is advantageous in terms of circuit design and service. Furthermore, since the aluminum board 11 constitutes a heat sink, it is not possible to replace the parts on this board 11 with a soldering iron, but with the above configuration, only the sub-board 11 needs to be replaced. There is no need to replace the entire composite board 30.

Sub-boards 9, 10 constituting the composite board 30,
Of the sub-boards 11 and 12, the sub-board 12 is composed of a phenol board with patterns on both sides, and as shown in FIG. This prevents components from being mounted at an extremely high density on only a portion of the surface of the composite substrate 30. In order to mount the component 51 on the back surface of the sub-board 12, it is sufficient to repeat the chip-shaped component mounting process shown in FIG. 3 once again. By combining the double-sided patterned sub-board 12 with the main board 8 in this way, it is not necessary to make the entire surface of the main board 8 patterned on both sides, and a large total cost reduction can be achieved.

By the way, in the above embodiment, the connection between the main board 8 and the subboards 9, 10, 11, and 12 is performed only by the adhesive resin 40 for attaching the chip-shaped circuit component 51, and this also provides the necessary and sufficient connection. However, when printing the protective coating resin 37 described above, this was applied to the joints between the main substrate 8 and the sub-boards 9, 10, 11, and 12, as shown in FIGS. 7 and 8. A protective coating resin 37 may be applied and the bonding strength may be reinforced by the adhesive resin 40.

Similarly, when printing the above-mentioned insulating resin 38, the insulating resin 38 may be applied to the bonding portion, and the bonding strength may be reinforced by the adhesive resin 40.

This is because even if the strength of the above-mentioned joint becomes excessive, there is no particular adverse effect, and the adhesive resin 40
This is because even if it is applied on the protective coating resin 37 or the insulating resin 38, no problem will occur.

Since the present invention has the above-described configuration, it is possible to combine the sub-board with the main board, which has a material or structure suitable for the performance of each circuit part, so that the performance of the circuit is improved by the circuit board. Therefore, an excellent hybrid integrated circuit can be provided.

Furthermore, according to the present invention, most of the composite circuit board can be constructed from a main substrate made of an inexpensive and easily processable material, such as a phenolic resin, which reduces the amount of expensive materials used. This reduces material costs.

Further, according to the present invention, since the sub-board is fitted into an opening having the same shape as the sub-board formed on the main board, the composite circuit board can be constructed flat without having any unevenness. For this reason, chip-like components can be automatically mounted on this composite substrate, and the productivity of this hybrid integrated circuit can be greatly improved.

Further, according to the present invention, when applying an adhesive resin for temporarily fixing the chip-shaped component to the circuit board, the adhesive resin is applied to the joint between the main board and the sub-board at the same time. Therefore, the sub-board is fixed to the main board. Therefore, there is no need to add a new process to fix the joint,
The cost of manufacturing circuit boards does not increase either.

[Brief explanation of the drawing]

The drawings show an embodiment in which the present invention is applied to a hybrid integrated circuit for audio, and FIG. 1 is a block diagram showing the manufacturing process of this hybrid integrated circuit.
Figure 2 is a flowchart showing the first half of this process, Figure 3 is a flowchart showing the latter half of this process, Figure 4 is a cross-sectional view of the aluminum sub-board, and Figure 5 is an exploded perspective view of the composite board. Figure 6 is a vertical cross-sectional view of the main part of a device for combining a sub-board with a main board, Figure 7 is a perspective view of a composite board coated with a protective coating resin, Figure 8 is a cross-sectional view of the same, and Figure 9 is a perspective view of a composite board coated with a protective coating resin. The figure is a perspective view of a composite board coated with a resin for bonding chip-shaped parts by printing, and Figures 10A to 10H are side views of essential parts of a printing device sequentially showing the operation of printing adhesive resin. Figure 11 is a cross-sectional view of a composite board printed with adhesive resin, Figure 12 is a perspective view of a composite board on which chip-shaped parts are mounted, Figure 13 is a cross-sectional view of the same, and Figure 14 is a cross-sectional view of the composite board with adhesive resin printed on it. 15 is a perspective view of the completed hybrid integrated circuit, FIG. 16 is a sectional view of the main part, and FIG.
FIG. 18 is a perspective view showing a modified example of the hybrid integrated circuit shown in the figure, and FIG. 18 is a sectional view of another portion of the circuit board shown in FIG. 15. In addition, in the symbols used in the drawings, 3... wiring pattern, 4, 5, 6, 7... rectangular opening, 8...
Main board, 9, 10, 11, 12... Sub board, 15
... Wiring pattern, 17 ... Silver electrode, 24 ... Wiring pattern, 28, 29 ... Wiring pattern, 30
. . . composite substrate, 40 . . . adhesive resin, 51 . . . chip-shaped parts, 64 . . . solder dip bath.

Claims (1)

[Claims] 1. Prepare a main substrate and a sub-substrate each having a predetermined conductive pattern formed thereon and having different materials or structures, form an opening in the main substrate in the same shape as the sub-substrate, and is inserted into the main board through this opening to be combined, and an adhesive resin for temporarily fixing the chip-shaped parts is applied to the combined circuit board, and the joint part between the main board and the sub-board is This adhesive resin is also applied simultaneously to the bonding portion of the main board and the sub-board, and the electrodes of the chip-shaped parts temporarily fixed by the adhesive resin are combined. 1. A method for manufacturing a hybrid integrated circuit, characterized in that the hybrid integrated circuit is electrically connected to a conductive pattern on a circuit board.